Nanosemiconductor material is the hot spot of material science research in recent 20 years. Compared with the conventional bulk phase semiconductor, since nanosemiconductor can create a quantum size effect, so it is possible to prepare the nanoparticle with different sizes which emits luminous emission of different frenquencies by controlling a certain reaction condition and thereby the objective of regulating luminous color can be attained. In addition, owing to the feature of nanodimension, the nanosemiconductor material is made to composite easily with organic polymer or small molecule material to prepare a film type luminous device by spin coating. CdS—, CdSe-nanosemiconductor has opened an attractive prospect for applying to photoelectric conversion. Now, a major breakthrough has been achieved in the field of the material research for electroluminescence and photocell etc. A. P. Alivisatos, Phys. Rev. B, 24(1996), 17628 reports a photoelectric conversion performance of MEH-PPV composite system (conversion efficiency increases up to 12% with the increase of concentration of CdS nanoparticle). M. G. Bawendi, J. Appl. Phys., 12 (1998), 7965 reports a double layer device made of shell/core structured CdSe/CdS-nanoparticle with PPV as a hole transfer material (quantum efficiency of luminous layer up to 0.1%, life 50-100 hr). Up to now, a great number of synthetic methods for preparing Groups II-VI (such as CdS etc) metal nanoparticles have been disclosed, such as the reverse-phase fine emulsion method, the organometallic chemistry method, and the aqueous solution method. The reverse-phase fine emulsion method can be used to produce a CdS nanoparticle with a uniform particle size distribution. However, it has a low luminous efficiency and can only emit a weak red light owing to many exterior and interior defects. The organometallic chemistry method requires a very harsh synthesis condition such as an oxygen-free and water-free operating atmosphere and uses toxic and costly reagents. The aqueous solution method will result in a wide nanoparticle size distribution and a defective luminescence.